I thought they were using NeXTSTEP, hence all the NS API calls in Obj-C. Back in 1989 I am guessing NeXT would be built on some kind of Unix system first. Consi

I thought they were using NeXTSTEP, hence all the NS API calls in Obj-C. Back in 1989 I am guessing NeXT would be built on some kind of Unix system first. Considering that OS X is a descendent of NeXT, I would think that before OS X, they would use it to run code, servers, etc.